An aqeuous solutino of Ni(No3)2 is green. Addition of aqueous solution Nh3 causes the color of the solution to change blue. If the ethylenediamine is added to the green solution, the color changes to violet. What causes the colors of these complexes? How do these colors relate to the expected positions of these ligands in the spectrochemical series?
Ni2+ has 8 d electrons. Under square planar coordinatoin, it's electron configuration is like the following:
-1 orbital a (dx2-y2)
-1 orbital b (dz2)
-2 orbital c (dxy)
-2 -2, orbital d (dxz, dyz)
where - stands for an orbital, the number means the number of ...
The solution uses the relevant ideas of molecule geometry and electron orbital transitions to answer the question of what causes the colors of certain complexes and how those colors relate to the expected positions of the ligands in their spectrochemical series.